bad display of data

AdamBalcar

When I upload my data they are shifted about 100 meters.
I don´t know where is the mistake. I use SHP files with S-JTSK coordinate system.
Thanks.

MikeMinamiP1

You need to transform your data... here's what our resident coordinate system expert said:

Sounds like a classic missing-transformation problem! I checked a reprojection in ArcMap with and without a transformation it was around 135m. An appropriate transformation would be S_JTSK_To_WGS_1984_5 or S_JTSK_To_WGS_1984_3.

When shapefiles are uploaded and added to a web map, no transformation occurs. If, however, you have an ArcGIS Online subscription and publish from ArcGIS for Desktop, we do transform the data.

Thanks,

Mike